Heat dissipation apparatus

ABSTRACT

A heat dissipation fan includes a first magnetic pole, and a second magnetic pole positioned in the first magnetic pole. A plurality of coils is positioned on the first magnetic pole. A plurality of fan blades is positioned on an inner surface of the second magnetic pole. When the current is applied, the magnetic field between the first and second magnetic poles generates a force on the first magnetic pole through the plurality of coils thereon. The first magnetic pole generates a counterforce on the second magnetic pole to rotate the plurality of fan blades.

This application is related to co-pending U.S. patent application Ser. No. 12/485,326, attorney Docket No. US23548, entitled “HEAT DISSIPATION APPARATUS”. The disclosure of the above-identified applications are incorporated herein by reference.

BACKGROUND

1. Technical Field

The present disclosure relates to a heat dissipation apparatus.

2. Description of Related Art

Electronic devices in computers, such as central processing units (CPUs), generate heat during normal operation, which can deteriorate their operational stability, and damage associated electronic devices if not dissipated. Thus, the heat must be removed quickly to ensure normal operation of the CPU. A typical heat dissipation apparatus includes a typical heat sink mounted on a CPU to remove heat, and a fan fixed on the heat sink to generate airflow through the heat dissipation apparatus. The typical fan includes a plurality of fan blades and a motor in the center of the fan for rotating the fan blades. However, the motor occupies some air intake area, lowering heat dissipation efficiency of the fan.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the embodiments can be better understood with references to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

FIG. 1 is an exploded view of an embodiment of a heat dissipation apparatus, the heat dissipation apparatus including a heat sink, and a heat dissipation fan.

FIG. 2 is an isometric view of an embodiment of the heat dissipation fan of FIG. 1.

FIG. 3 is an assembled view of the heat dissipation apparatus of FIG. 1.

DETAILED DESCRIPTION

FIG. 1 is an exploded view of an embodiment of a heat dissipation apparatus. The heat dissipation apparatus includes a heat sink 10, and a fan 20 configured to be fixed on the heat sink 10.

The heat sink 10 includes a base 11, and a plurality of radial fins 12 formed on a top surface of the base 11. A bottom surface of the base 11 is configured to contact a heat source, such as a central processing unit (CPU). The heat generated by the heat source is transmitted to the fins 12 via the base 11. The fins 12 extend upwardly at an angle from the top surface of the base 11 to form a series of truncated cones in the middle of the heat sink 10. A cross section of the truncated cones gradually increases from the top surface of the base 11 to a top end of the fins 12. A top of the truncated cones forms an air inlet for the fan 20. A plurality of guiding members 13 is formed behind the outmost fins 12 to define a plurality of air outlets 14 between adjacent fins 12. The air flows in the heat sink 10 from the air inlet, through the fins 12 and out of the air outlets 14.

Referring to FIG. 2, the fan 20 includes a first magnetic pole 21, and a second magnetic pole 22 positioned in the first magnetic pole 21. The first and second magnetic poles 21, 22 are ring shape. A plurality of coils 27 wraps around the first magnetic pole 21. The plurality of coils 27 is electrically coupled to a motherboard (not shown) of a computer (not shown), and is capable of receiving a direct current from a power supply (not shown). A plurality of fan blades 23 is secured on an inner surface of the second magnetic pole 22. The fan blades 23 extend from a connection point 24 at a hub of the fan blades 23 to the inner surface of the second magnetic pole 22, and can be symmetric with respect to the connecting point 24. An axle 25 extends outwards from the connecting point 24. The axle 25 is secured to the first magnetic pole 21 via a plurality of supporting ribs 26. A thickness of the first magnetic pole 21 is greater than that of the second magnetic pole 22. The magnetic property of an inner surface of the first magnetic pole 21 is opposite to that of an outside surface of the second magnetic pole 22. In this embodiment, the plurality of fan blades 23 is integrally formed on the inner surface of the second magnetic pole 22.

Referring to FIG. 3, the fan 20 is mounted on the heat sink 10 aligned with the air inlet of the heat sink 10. The fan 20 is mounted to the heat sink 10. When the direct current is provided to the coils 27, the magnetic field between the first and second magnetic poles 21, 22 generates a force on the first magnetic pole 21 through the plurality of coils 27 thereon. The first magnetic pole 21 generates a counterforce on the second magnetic pole 22, and drives the second magnetic 22 to rotate relative to the first magnetic pole 21. The second magnetic pole 22 rotates around the connecting point 24 and axle 25 to thus rotating the plurality of fan blades 23. It is known that the force that will act on the second magnetic pole 22 is proportional to the number of the coils 27 and strength of the current flowing through the coils. The rotating speed of the fan 20 is adjustable by changing the number of the coils 27 and/or adjusting the current through the coils. According to the heat dissipation apparatus of the disclosure, the coils 27 and the plurality of fan blades 23 are spaced apart from each other. Thus providing more air flow efficiency when compared with the typical fan. The motor of the typical fan is omitted, and air intake for the fan 20 is unobstructed. When the fan 20 rotates, air intake area of the fan 20 can better receive airflow, and efficiency of heat dissipation is improved. The number of the coils 27 on the first magnetic pole 21 of the disclosure is unlimited and can be increased as required to increase the rotating speed of the fan 20. Therefore, efficiency of heat dissipation is further improved.

It is to be understood, however, that even though numerous characteristics and advantages of the embodiments have been set forth in the foregoing description, together with details of the structure and function of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. 

1. A heat dissipation fan, comprising: a first magnetic pole having a plurality of coils thereon; and a second magnetic pole having a plurality of fan blades secured therein, the second magnetic pole positioned in the first magnetic pole; wherein when a current is applied, the magnetic field between the first and second magnetic poles generates a force on the first magnetic pole through the plurality of coils thereon, the first magnetic pole generates a counterforce on the second magnetic pole to rotate the plurality of fan blades.
 2. The heat dissipation fan of claim 1, wherein the first and second magnetic poles are ring shape.
 3. The heat dissipation fan of claim 2, wherein the plurality of fan blades is integrally formed on an inner surface of the second magnetic pole; the fan blades extend from a at a hub to the inner surface of the second magnetic pole and are symmetric with respect to the connecting point.
 4. The heat dissipation fan of claim 3, further comprising an axle that extends outwards from the hub.
 5. The heat dissipation fan of claim 4, wherein the axle is connected to the first magnetic pole via a plurality of supporting ribs.
 6. The heat dissipation fan of claim 2, wherein a thickness of the first magnetic pole is greater than that of the second magnetic pole.
 7. The heat dissipation fan of claim 6, wherein the magnetic property on an inner surface of the first magnetic pole is opposite to that of on an outside surface of the second magnetic pole.
 8. A heat dissipation apparatus, comprising: a heat sink contacting a heat source, comprising: a base with a bottom surface contacting the heat source; a plurality of radial fins angling upwardly from a top surface of the base; and a fan positioned on a top of the heat sink, comprising: a first magnetic pole having a plurality of coils thereon; a second magnetic pole having a plurality of fan blades secured therein, the second magnetic pole positioned in the first magnetic pole; wherein when a current is applied, the magnetic field between the first and second magnetic poles generates a force on the first magnetic pole through the plurality of coils thereon, the first magnetic pole generates a counterforce on the second magnetic pole to rotate the plurality of fan blades.
 9. The heat dissipation apparatus of claim 8, wherein the first and second magnetic poles are ring shape, the magnetic property on an inner surface of the first magnetic pole is opposite to that of on an outside surface of the second magnetic pole.
 10. The heat dissipation apparatus of claim 8, wherein the top of the heat sink forms an air inlet, the fan is mounted to the heat sink.
 11. The heat dissipation apparatus of claim 8, wherein the heat sink further comprises two guiding members formed behind each outside fin to define an air outlet therebetween, with airflow from the fan passing through the fins and out the air outlet.
 12. The heat dissipation apparatus of claim 11, wherein the fins and guiding members are integral with the base. 